木星外磁层结构的定态模式

本文建立了描述木星外磁层结构的磁流体力学方程组,在这一方程组中考虑了磁层转速和等离子体片倾角(等离子体片与旋转赤道平面的夹角)随径向距离的变化。在不同条件下对此方程组求解,得出了等离子体片中各变量(磁场、压力、温度、质量密度和电流密度)的空间分布表达式。结果表明:各变量随Z(离开赤道平面的距离)的变化可用两种函数形式表示,一种是双曲线函数,这种分布形式与观测结果相符合;另一种是三角函数形式。各变量随径向距离r的关系是:压力P_o(r)～r-3.4,电流密度i_o(r)～r-1.7.对于绝热过程,密度ρ_o(r)～r-2.04,温度T_o(r)～r-1.36;对于等温过程,密度ρ_o(r)～r-3.4,温度T_o=常数。最后讨论了木星磁异常对外磁层结构的可能影响。 

A STATIC STRUCTURAL MODEL OF THE OUTER MAGNETOSPHERE OF JUPITER

In this paper the ideal-state MHDequations are solved: the results show that there are two kinds of relationship between the variables and Z (the distame from equator) in the plasma sheet.One is a hyperbolic function,while the other is a trigonometric function.Observations would seem to agree with the hyperbolic function.Simple distribution formulas of pressure,density,temperature,magnetic field and current density in the plasma sheet are deduced.The relationship between the variables and radial distance r are: P_o(r)～r-3.4,j_o(r)～r-1.7. For an adiabatie proceess,p_o(r)～r-2.04,T_o(r)～r-1.36.For an isothermal process,p_o(r)～r-3.4,T=constant.Finally,the influences of the magnetic anomaly on the outer magnetosphere are dicussed.